Plug and jack



Aug.24,1937. I A, M, LEWYT 2,090,761

- PLUG AND JACK I Fil ed Aug. 15,' 1955 2 Sheets-Sheet 1 11v VENTOR ATTORNEY Aug. 24, 1937. A, M, LEW T 2,090,751

PLUG AND JACK Filed Aug. 15, 1955 2 Sheets-Sheet 2 INVENTOR ATTORNEY and jack members.

Patented Aug. 24, 1937 PATENT @FFHQE PLUG AND JACK Alexander M. Lewyt, New York, N. Y. Application August 15, 1935, Serial No. 36,279

1 Claim.

This invention relates to a plug and jack. More particularly, the invention relates to a plug and jack used for making an electric coupling between one or more sets of wires in circuits where the 5 resistance factor, and a positive locking and contacting are extremely important. Particular commercial applications for which my plug and jack are intended are sound apparatus, radio broadcasting apparatus, heavy duty stage lighting apparatus, and other applications of similar nature.

Plugs and jacks of various types have been known for many years and have been very highly developed in this art. Yet, I have conceived a' 35 plug and jack operating in a new combination and producing extremely meritorious and novel results. While the improvements which I have devised are naturally applicable only in a narrow field, yet they are of extreme importance in that 520 narrow field, and my final conception as embodied in my invention, I believe to be a definite contribution to this art.

As a feature of my invention, I utilize open end metal housings for each of my cooperating plug Each of the metal housings is adapted to house an insulation block which preferably is shouldered so that it may enter the open end of the housing for only a certain distance. The size of each housing relatively to the 30 inserted block is such that there is a relatively large space between the end of the block and the closed end of the housing, into which space wiring may be placed, or the wiring may be knotted. The results obtained through providing this air 35 space are extremely worthwhile.

Each insulation block member is bored for the insertion of contact members, the contact members lying partially in the bores of the insulation block and partially on an exposed surface. The

49 wires are naturally led from the open space be tween the end of the block and the housing to this exposed surface, and are joined to the contact members by a usual type of screw. Should there be any loose strands of wire, there would naturally be a short circuiting.

To avoid this, I take a strip of insulation paper and place it within the housing. Then, on inserting the insulation block member, the paper is held in position. Since the exposed surfaces previously describedare on opposite sides of the insulation block member, it is readily observed that a single strip of paper properly folded will accomplish the particular purpose intended.

For maintaining the insulation blocks within the housings, I utilize screw members running from the outside of the housing into screw threaded bores in the individual blocks. I use preferably two screws on each of the opposite sides of the housing member. Preferably, on one side I use round head screws, and on the other side, I use flat head screws. By using the different combinations of screws on corresponding sides of the plug and jack, I am able to get an indicating action, since, in the dark, an operator need only feel the screws to snow just how to connect the two cooperating members.

It is extremely desirable to have the contact members, both male and female, float in the individual insulation blocks. I therefore have my contact members of smaller size in external diameter than the bores in which they are mounted. The contact members are inserted axially into the bores, part being adapted to overlie the exposed surface previously described. The part lying on the exposed surface is that portion of the contact member which isadapted to :be secured to the wiring, and it is threaded for a screw adapted to secure the wiring. There is also a transverse bore leading from the exposed portion internally into the plug. This bore is unthreaded. As a screw is placed into the threaded portion of the contacting member, and is driven home to secure the wires to that member, part of the screw will enter the unthreaded transverse bore of the block.

It will be readily appreciated that the screw will prevent movement in two directions of the contact member, while permitting pivoting movement of the contact member about the axis of the screw. It will also permit the contact member to move up and down on the axis of the screw, and such up and down movement, as well as the pivoting movement indicated, is possible within the limits of the clearance between the contact members and the bores in which they are mounted. By this rather ingenious method, I am able to obtain a floating contact member, and at the same time, I am able to secure the contact member relatively to the housing by the most simple means possible.

The female contact member of my invention is, I believe, most ingenious. This member comprises a pair, or there may be more, of segments which are adapted to lie with their end surfaces in contact, and are maintained contacted by an ex pansible spring. This spring is furthermore so arranged that it not only maintains the segments against one another, but maintains the segments against movement in the direction of their length, thus keeping them entirely assembled.

Briefly, the internal surfaces of the segments are parts of a circle of the same diameter as the male contact member to be inserted between the segments, but of course, form less than the complete circumference of such a circle. Also, the internal surfaces of the segments have a groove therein which cooperates with a lip member on the male contact member for locking the two together. I obtain a pivoting and wiping action of the segments relatively to the male member as the male member is inserted between the segments, and which wiping action is of extreme importance and will be emphasized later.

As a further feature of my invention, I have means for clamping the cable, or other wiring, to the housing of my invention, which I feel is rather important and which will be indicated more specifically later on.

For a description of a preferred embodiment of my invention, I shall now refer to the drawings,

wherein Fig. l is a plan view showing the housing carrying the male contact members. Fig. 2

is a similar View of the housing carrying the female contact members. Fig. 3 is a view of Fig. 2 taken floating positions which may be assumed by the female contact members. Fig. 4 is a plan View of the plug of Fig. 3 looking at Fig. 3 in the direction of arrow 6. Fig. 5 is an end view of Fig. 4 showing the various positions which may be assumed by the contact members relatively to the plug. Fig. 6 is a section view taken along lines E-6 of Fig. 3 showing the method of mounting a female contact member, while Fig. 7 is a corresponding view illustrating the mounting of a male contact member. Fig. 8 shows the method of insertion of a plug into the housing and shows the placing of the insulation paper in the housing. Fig. 9 illustrates the joining of the male'and female contact members, while Fig. 10 shows them in the process of being joined. Figs. 11 and 12 are individual views of the contact members. Fig. 13 is a view taken along lines l3l3 of Fig. 11, while Fig. 14 is an end view of the spring used to hold the segments of the female contact members in position. Fig. 15 is an end View along lines i5-l5 of Fig. 2 and illustrates the means for binding the cable relatively to the housing.

Before referring more particularly to the draw- 5O ings, it should be emphasized that there is no' difference between the male and female contact carrying blocks and housings, so that the description of one housing will sufiice for both. Since the means for securing the contact members is also the same, the description will be entirely limited to the female carrying block and its housing member illustrated in Fig. 2.

Referring now to Fig. 2, reference numeral l0 indicates a square metal housing member having an open end II and a closed end [2. Naturally,

I could use a sleeve-like housing if I desired, in

combination with the additional features of my invention. An insulation block member l3, illustrated in Fig. l, is inserted into housing l0 until its shoulder portion I 4 impinges against the surface I I, whereupon it is secured in position by opposite pairs of screws l5 and I6 entering pairs of threaded bores l1, illustrated in Fig. 8. It will be noted that the screws I 5 have fiat heads, while the screws [6 have round heads. The shapes of the screw heads are important since they serve to indicate to an operator the relation of the contact members. The male carrying member has a similar arrangement, as illustrated in Fig. 1, and the operator by the feeling of the screws will along line 3-3 of that figure and illustrating the know just how the two members ought to go together. Of course, the contact members are staggered in such a way that they will only go together in one position, but for quick coupling in the dark, these screws are extremely valuable.

Between the end surface l8 of the block l3 and the closed end l2 of the housing, there is an air space l9 in which will be housed part of the cable 20, to permit for knotting of the wire strands, or for twisting of the cable, so as to permit of better entry of the wire strands into engagement with the contact members.

The contact carrying block [3 has a series of bores 2|, each of which is adapted to house a contact member 22 which is inserted endwise into the bore, as is probably best appreciated by viewing Fig. 6. It will be observed that the contact member 22, which in Fig. 6 is a female contacting member, is of such size that even when properly expanded, as will be indicated later, it may float within the bore 2| because of the clearance between it and the bore.

The bore 2| leads to an open exposed space 23 which has leading therefrom a bore 24 transverse to the bore 2!. This bore 24 is not threaded, but is adapted to have entered therein a contact making screw 25 which secures a wire strand 26 of the cable 20 to the contact member 22, as is best appreciated from viewing Fig. 6. Naturally, the contact member 22 will be able to rotate within the bore 2| about the axis of the screw 25. Similarly, it will be able to move axially along the axis of screw 25 in the bore 24 within the limits permitted by the clearance between the contact member 22 and the walls of the bore 2 I. The permissible floating of the contact members 22 is probably best illustrated in Figs. 3 and 5. In Fig. 3, the contact members 22 are shown as occupying various positions relatively to the bores 2!. In Fig. 5, the opposite ends of the contacts 22 and the screws 25 are similarly seen as occupying various positions relatively to the block member l3, all of which will be readily appreciated by those skilled in the art.

Each male contact member 30 is secured within a bore 3| in its block l3 in quite the same manner as is each female member 22, a male member being best illustrated in Fig. '7. It also has a contact fastening screw 25 operating in a bore 24 in the same manner as the screw 25 cooperating with contact member 22 in Fig. 6. The particular cooperation between the contact member 30 and the contact member 22, and the particular construction of the two members, will be emphasized later in this specification.

In Fig. 8, I illustrate the method of inserting the insulation block l3 into the housing l0. In this figure, I also illustrate the use of the insulation strip 32 which is necessary to obviate short circuiting due to short strands of wire escaping the contact making screws 25. The insulation strip 32 is placed in the housing, as shown in Fig. 8, and it is designed only for covering the exposed portions 23 of the block I3, the exposed portions being on the upper and lower surfaces of the block member l3, looking at Fig. 8. The wire strands 26 of the cable 20 are first secured by the screws 25 to their contact members, and the block I3 is then pushed into the housing l0 until its shoulder I3 abuts the surface I I, thus securing the insulation strip 32 in proper relation.

The housing I 0 has an extending lip 35 formed integrally therewith, as best shown in Fig. 8, and cooperating with this lip 35 is a plate 36 connected to the lip 35 through the intermediary of screws 31 and 38, as best illustrated in Fig. 13. The member 36 or lip 35, or both, may be equipped with ribs 39 which, when the screws 31 and 38 are driven home, enter into the cable 2|] for holding it tightly in position, thus removing any possible strain from the wire strands 26 and their connection with the contacts through screws 25.

In Fig. 11, I illustrate my female contact member, which comprises the cooperating main portion 22 and a cooperating segment 22a. While I prefer to have two cooperating portions or segments, it will be readily appreciated that there may be more of these segments. The internal surfaces 43 of the portions 22 and 22a are formed as parts of the circumference of a circle whose diameter is that of the diameter of the male contacting portion 30a of the male contact mem ber 30. A groove 4| is formed on the outside surface of the members 22 and 22am and in this groove 4| will lie a spring 42 of somewhat elliptical shape, and which holds the two segments 22 and 22a together, as best illustrated in Fig. 13, in which figure it is seen that because the segments are only parts of a complete circle, they must form a substantially elliptical shape with their internal surfaces 40.

The segments 22 and 220. also have aligned grooves 45 cut in their internal surfaces 40, which grooves cooperate with a lip 43 on the male contact 30.

In Fig. 10, I illustrate the action when the portion 30a of the contact member 33 enters between the segments 22 and 22a, which lie at first with their end surfaces 44 and 44a in juxtaposed relation, as best seen in Figs. 11 and 13. It will be noted that the segments 22 and 22a are first tilted relatively to one another against the action of the spring 42, and as the member 3011 enters therebetween, they will be spread gradually until finally the parts will assume the position of Fig. 9, wherein the internal surfaces 40 of the segments 22 and 22a have assumed a position in full contact with surface 30a. of'the contact member 30 and with their end surfaces 44a and 44 separated. In this way, I obtain a very positive wiping action between the contacts which acts to clean them each time contact is made. I obtain also a positive locking due to the cooperation of the lip 33 with the internal groove 45, and I obtain physical engagement between considerable areas of the contact members so that the possibility of looseness in the contacting engagement is eliminated, and so that resistance in the electric coupling is practically non-existent.

While I have now described rather in detail an embodiment of my invention, I should like to indicate once again that I consider my invention to be of relatively great importance in the particular narrow field of this invention, and I feel myself entitled to a relatively broad monopoly along the lines of the claim hereinafter appended.

I claim:

In a combination of the class described, an insulation block, a bore in said block leading to an exposed accessible surface, a contact member of semi-circular section adapted to lie partially in said bore and partially on said exposed surface, a cooperating contact member of semicircular section in said bore only, and forming a complete female contact member with said first contact member, a fiat spring for holding said contact members assembled, said members when assembled being smaller than said bore so as to float therein, whereby to allow separation and expansion of said contact members within said bore against the pressure of said spring when a male contact element is inserted therebetween, the insertion of said male element being adapted to separate the said contact members at their outer ends by the relative tilting of said members, the contacting surfaces of said members being thereafter gradually separable as said male element is fully entered between said contact members, a bore transverse relatively to said first bore leading internally into said block from said exposed surface, a threaded opening in that portion of the first contact member lying on said exposed surface, and a wire securing screw insertable into said threaded opening and adapted to enter said transverse bore as it moves into wire holding relation to said contact member.

ALEXANDER M. LEWY'I. 

